A160917 Averages of twin prime pairs which can be represented as a sum of three consecutive of such pair averages.
60, 282, 348, 522, 570, 618, 1788, 2112, 4050, 4422, 5880, 6198, 8232, 9678, 10458, 11700, 12072, 12162, 12378, 14010, 16140, 17598, 17838, 21648, 22698, 33348, 36342, 39228, 41610, 43782, 44088, 46272, 48780, 51198, 53088, 56910, 58230
Offset: 1
Keywords
Examples
a(1) = 60 = A014574(7) = 12 + 18 + 30 = A014574(3) + A014574(4) + A014574(5). a(2) = 282 = A014574(19) = 72 + 102 + 108 = A014574(8) + A014574(9) + A014574(10).
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Harvey P. Dale)
Programs
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Mathematica
PrimeNextTwinAverage[n_]:=Module[{k},k=n+1;While[ !PrimeQ[k-1]||!PrimeQ[k+1], k++ ];k];lst={};Do[If[PrimeQ[n-1]&&PrimeQ[n+1],a=n;b=PrimeNextTwinAverage[a]; c=PrimeNextTwinAverage[b];a=a+b+c;If[PrimeQ[a-1]&&PrimeQ[a+1],AppendTo[lst, a]]],{n,8!}];lst Module[{m=Mean/@Select[Partition[Prime[Range[10000]],2,1],#[[2]]-#[[1]] == 2&],t},t=Total/@Partition[m,3,1];Intersection[m,t]] (* Harvey P. Dale, Mar 06 2018 *)
Extensions
Comments moved to the examples - R. J. Mathar, Sep 11 2009
Comments